~ A blog about IQ, the brain & success

Tag Archives: Brain Size blog

My recent post about how readers of brainsize.wordpress.com have an average IQ of 147 was damaging to the self-esteem of many readers. For example a reader named “Andrew” wrote:

I suppose I’m the dunce around here with an IQ of ~120!

Intelligence is relative, so even though an IQ of 120 is higher than 90% of the U.S. population, when you find yourself on a blog like this one where the average IQ is said to be 147, an IQ of 120 can feel extremely low.

Well the good news for all the “Andrews” out there is that my readers do not have an average IQ of 147 after all. That figure was arrived at using remarkabley indirect evidence. A poll I conducted found that the average reader was about 0.62 standard deviations taller than others of their demographic group, and since height is thought to correlate 0.2 with IQ, I simply dividing their average height (+0.62 SD) by 0.2, to estimate their average IQ to be 3.1 SD above the mean (IQ 147).

There were a couple problems with this however. For starters, as more readers have started to vote in the height poll, it seems the average reader is 0.43 SD taller than normal, not 0.62 SD as previously estimated. Secondly, while 0.2 is the correlation between IQ and height, what I really want is the correlation between height and g (general intelligence) and I want it corrected for reliability. This figure would be about 0.26.

So now with the revised height (+0.43 SD) divided by the true g loading of height (0.26), it seems Brain Size readers have an average general intelligence of 1.65 SD above normal. In other words, Brain Size readers average an IQ of 125. This is a far more believable figure than 147, which is about what you’d expect from the average academic Nobel Prize winner.

Many people are confused by why I divided the height of my readers (+0.43 SD) by the true g loading of height (0.26), instead of just multiplying it. For example, NBA players are ridiculously tall (perhaps +3.88 SD taller than other American men in their age group). If I wanted to estimated the average IQ of NBA players from their average height, would I divide their height by the g loading of height? If so, their estimated intelligence would be +14.92 SD (an average deviation IQ of 324 making the average NBA player more than 100 IQ points smarter than any person who ever lived!) So instead of dividing their height (+3.88 SD) by 0.26, I would multiply, which gives an estimated intelligence of +1 SD (IQ 115).

I know I said my next post would be about heritability, but there’s been some major news for this blog and I must take a moment to thank the Lion of the Blogosphere, who by writing about me yesterday on his wildly popular blog, drove the number of unique visitors and page views to far and away the highest level in the entire history of either of my blogs. And then by blogging about me again today, drove the web traffic far higher than even yesterday, and the day’s only half over!

The Lion is an extremely bright and talented blogger and can very effortlessly attract and maintain a huge readership through witty and insightful social observations and by writing succinctly and clearly. It’s a huge honor that he would so generously share his enormous readership with my little blog two days in a row. I read and comment on his blog constantly because he writes about IQ, success and social class, and does so with an understanding of the Ivy League elitism in New York city (where he lives) which is quite fascinating and horrifying for a Canadian like myself (no such caste system exists here in Canada).

I was honored to discover that Professor Bruce Charlton had written the following:

…a new blog called Brain Size…Which is shaping-up to be a valuable contribution to intelligence research.

The author, Herr Professor Doktor Pumpkinperson, has the attributes of honesty, persistence (this especially), intelligence and a refreshing disinclination to take offense at the criticism of others!

I greatly appreciate the compliment, especially coming from a man of such towering intelligence and integrity, and one who is so eminent that his ideas are discussed by the world’s most influential newspaper. I don’t think this blog is worthy of praise from such a high quality source, but hopefully it will become more worthy over time.

Charlton is enormously respected for his original thinking and willingness to courageously challenge the scientific consensus on many issues, and strongly defend the right of others to do so too, thus playing an invaluable role in both academia and the blogosphere.

I can not recommend his blogs strongly enough, especially Intelligence, Personality and Genius. Although I disagree with some of his ideas, his blogs have been a treasure trove of insightful and informed fascinating observations. He discusses many of the same topics I do, but does so with much greater knowledge and understanding and from a multidisciplinary perspective that very few people have. It’s very rare for that quality of writing to be so freely available and accessible to anyone with internet access, so I strongly recommend one take advantage of it.